(SEM VII) THEORY EXAMINATION 2023-24 SOFTWARE ENGINEERING

SECTION A – Very Short Answer Type

(2 × 10 = 20 Marks)

a) Software Engineering

Software Engineering is the systematic, disciplined, and quantifiable approach to the development, operation, maintenance, and retirement of software.

b) Components of Software

The main components of software are:

Programs (code)                            Documentation                            Operating procedures

c) Software Crisis

Software crisis refers to the difficulty of developing large, complex, and reliable software systems within time, cost, and quality constraints.

d) ISO 9000 vs SEI-CMM

ISO 9000 focuses on quality management standards, while SEI-CMM focuses on process maturity levels for software development organizations.

e) Top-Down vs Bottom-Up Design

Top-down design starts from the overall system and breaks it into modules, whereas bottom-up design builds the system by integrating small components first.

f) Control Flow Graph

A control flow graph represents all possible paths through a program using nodes and edges, mainly used in white box testing.

g) Failure vs Fault

Fault is a defect in the software.

Failure occurs when the software behaves incorrectly due to a fault.

h) Importance of White Box Testing

White box testing ensures internal logic, loops, and conditions are tested, improving code quality and coverage.

i) Reasons for Increase in Software Cost

Increasing software complexity

Frequent requirement changes

j) Software Configuration Management (SCM)

SCM is the process of tracking, controlling, and managing changes in software throughout its life cycle.

SECTION B – Long Answer Type

(Attempt any three – 10 Marks each)

2(a) Waterfall Model

The Waterfall Model is a linear sequential model where each phase must be completed before the next begins.

Phases:                                                                Requirement analysis

System design                                                     Implementation

Testing                                                                 Deployment

Maintenance

Advantages:                                                         Simple and easy to understand

Well-defined stages                                             Suitable for small projects

Disadvantages:                                                    No flexibility for changes

Late testing                                                         Not suitable for large or complex projects

2(b) Decision Tables

Decision tables are used to represent complex business rules clearly.

Components:                                                       Condition stub

Condition entries                                                 Action stub

Action entries                                                      Bookstore Decision Table (Summary):

Decision tables help remove ambiguity in decision-making.

2(c) Cohesion and Coupling

Cohesion:

Measures how closely related the functions within a module are.
 

Types: Coincidental, Logical, Temporal, Procedural, Communicational, Sequential, Functional.

Coupling:

Measures interdependence between modules.
Types: Content, Common, Control, Stamp, Data.

High cohesion and low coupling are desirable for good software design.

2(d) Test Drivers and Test Stubs

Test Driver: Simulates calling module (used in bottom-up testing).

Test Stub: Simulates called module (used in top-down testing).

They enable early testing and fault isolation.

2(e) Cost Analysis and COCOMO Model

Cost analysis estimates effort, time, and cost of software development.

COCOMO Model:                                         Effort = a × (KLOC)^b

Types:                                                           Basic COCOMO

Intermediate COCOMO                               Detailed COCOMO

It helps in project planning and budgeting.

SECTION C – Descriptive Answer Type

3(a) Spiral Model and Risk Analysis

The Spiral Model combines iterative development with risk analysis.

Phases:                                                        Planning

Risk analysis                                                Engineering

Evaluation

Risk analysis identifies technical, schedule, and cost risks early, reducing project failure chances.

3(b) Software Development Life Cycle (SDLC)

SDLC defines stages of software development:

Requirement analysis                                 Design

Coding                                                       Testing

Deployment                                               Maintenance

It ensures systematic development and quality assurance.

4(a) Importance of SRS and IEEE Format

SRS defines what the software should do.

Importance:                                               Acts as a contract

Reduces ambiguity                                    Basis for design and testing

IEEE SRS Format:                                        Introduction

Overall description                                     Functional requirements

Non-functional requirements                    External interfaces

4(b) Requirement Elicitation

Requirement elicitation gathers user needs and expectations.

Techniques:                                                Interviews

Questionnaires                                          Observation

Workshops                                                Prototyping

5(a) Top-Down vs Bottom-Up Design

Top-Down:                                                 Easy understanding

Early system overview                                Needs stubs

Bottom-Up:                                                Reusable components

Easy testing                                                Needs drivers

Both have advantages depending on project type.

5(b) Halstead’s Software Science

Halstead metrics measure:                        Program length

Volume                                                      Difficulty

Effort

They help estimate program complexity and development effort.

6(a) Software Design Strategies

Design strategies include:                          Modular design

Structured design                                       Object-oriented design

Good design improves maintainability, scalability, and reliability.

6(b) Formal Reviews, Walkthrough, Code Inspection

Formal Technical Review: Structured peer review

Walkthrough: Informal review led by author

Code Inspection: Detailed line-by-line analysis

7(a) Software Maintenance

Maintenance is required to:                           Fix bugs

Adapt to changes                                           Improve performance

Types:                                                              Corrective

Adaptive                                                          Perfective

Preventive

7(b) Risk Management

Risk management identifies and controls project uncertainties.

Types:                                                            Project risk

Technical risk

Project risks affect schedules and cost, while technical risks affect performance and quality.